In heterostructures with a (001) interface, and diamond and sphalerite crystal lattices, the total relief of mismatch stresses by introducing 2 mutually perpendicular arrays of 60° misfit dislocations was shown to be possible only if their screw components were of the same type. Otherwise, it was necessary to introduce additional misfit dislocation arrays which increased the formation probability of threading dislocations in an epitaxial film. When the process was non-optimum, and 2 mutually perpendicular arrays were introduced having opposite types of screw component, the excess energy of long-range shear stresses accumulated. Typical examples of the non-optimum introduction of misfit dislocations were the operation of Frank–Read and Hagen–Strunk modified dislocation sources.

Influence of the Misfit-Dislocation Screw Component on the Formation of Threading Dislocations in Semiconductor Heterostructures. E.M.Trukhanov, A.V.Kolesnikov, A.P.Vasilenko, A.K.Gutakovskiĭ: Semiconductors, 2002, 36[3], 290-7